Valve for pneumatic riveting hammers



Patented Aug. 19, 1952 I g Ernes t H. .Fors s,"R ockford, Ill.,assi gnor me sne" 1 assignments, to Skilsaw, Inc'.,",Chicago', 111., a corporation'of Delaware g Application'November 3, 1944, 'seiinsasefls This invention relates; to improvements in pneumatic riveting hammers and, has .for .its principal object the provision of a slow-hitting hammer having such fine control oi air delivery that .asin 1e li h ra ma be ven. the-r ve set,-thus better adapting the tool; to .use ir airjplane manufacturing plants where. the light; rap servesas a signal from the operator on the outside of an airplane. fusela e to his or her helper inside who backs up the rivets which rivet will 7 next be hammered, thus reducing to a minimum any likelihood of therelatively f r a il aluminum wall that is being rivetedbeing dented, oneven punctured, and requiring removaLpr .-,a lar e panelas a'result of the' failure on thepar't oi I Successful, riveting, whether done by skilled or semi-skilled workers; depends to a very. large extent on the operators ability to control. the movementof the throttlevalve. Small riveting hammers naturally require only a small volume or. air. It is, therefore, necessaryfor the oper ator of such a hammer to he able to control the m vement. of the tri er; o t a he Naiv may be opened at a uniform rate,=; 1 -v An improvement in trigger eontrql .ov er ;the existing and conventional types is especially desirable in the offset handletype of hammers to, which this invention. refers. The vreasorris that in this type of hammer the movement of the I helper. to back up the proper .rivetlthe triggerv is in the opposite 7 direction to the pressure applied bythe operators hand for holding the rivet set on the rivet.

By using the novelfeature of a double guide the trigger invthe hammerof my inventioncan be made wide enoughtoprovide a comfortable grip for-two or three fingers. This enables the operator. to eflect uniform movement of the trigger by the squeezing of his or her hand around the handler Another feature'of thisconstruction is that theeomfortable two or three fingergrip reduces finger fatigue or cramp which is greatly appreciated, especially by female operators. I,

.-.The invention is illustrated in the accompanyingdrawing, in which-.- r 4 I v1.,is a longitudinal section through a pneumatic riveting hammer embodying my innt o Fig, 2 is an enlarged sectionaldetail of the throttle valve, and. J 4

Fig. 3 is a section on an enlarged scale. s

The same reference numerals are applied to corresponding parts throughout the view s.

The hammerlcomprises a barrel portion- 4 in which a bore-.5 is providedforthereciprocable piston 6, adapted to strike the innerend of the shank?!- of the rivet set 8 enteredqinthe outer endsofpthe bore. The rivet set is retained by through the. lair. regulator gheehive spring; 9 j mou ntd on. the outer .1 he a he ih t leva vfif .m inv' nr H enerallyby the; reference numerale Q i s he d iver r t th valve mechanism II which fits inside the counter- -h'ore l z in the rear end portion [3 of the .barreland is arranged to directthe air .alternately to the opposite ends of thebore fi -so. as topropel the pist n B-hack and forth. The. valve meehanism l l. is .of a well known formand no invention is lai e nan eo t d l t ereqf- The r hd portiop; l 3 of' the barrel is externally thread; dr9ona 1 ts the upper lend e tin 1. 9:. th h d e th et er ei m n n t r aded ssin eiedat 1 r" u h n e t n;- l-i th a in et Op ning 0 h h sm.. ;.n e .i h .ha dlq wand. is the. e a s O e r vid d h re d portion of thebarrel, and I 9 is a split sheet metai deflector ring to direct. theexhausting airf down wardly. in the operation .of-theharrimer.

. Thethrettle valve l0, in ccordance with .my invention comprises atapered but nearly Gynadrical head 20 ona stem. 2|, reciprocable my; guide}; provided thereforfin a; valve bushing The. er .i zih eeded esn i a e a for eeei lvq M Pr v d d at e a dle ISTand is'locked in place by apin 23 'driven intoregistering'holes in the handleand bushing. The bushing is counterbored and radially ported at its. innerend, there being a series of radial ports 26 in a smaller counter-bore on one side of the valve seat Z'IcOmmunicating withfthe inlet sion .3437 in., plus DOGS-in., and the head jllis r .3420. in. at the small end; next to the bevelpo r-v tion. 29 that cooperates withthe seat 21;, and-is .3437 -r m s 0 a t e l e n and thehead-Zflis of-sfuch length in relation-to the bore, as... indicated in Fig. 2-,'.that the large end projects-only slightlyfrom the counterbore when'the' throttle valve is closed... The parts, in other words, are shown exaggerated in Fig. 2, in orderbetter to illustrate the tapered clearance but. in actual manufacture-there is only :a very small clearance between. the large end. of the head 20 and the. counterbore 28 when the valveis closed. A coiled compressionspring 30 engages at one end in a socket-.3! 'provided'thereior in causing,fatigue forithe-Operator ultimately- 5:50

the k. we lpf the ha l5 n a ts M er end fits even, reduced pilot portion "32 provided on the back'of the head 20, and tends normally to hold the valve closed. The valve is arranged to be opened by depression of the trigger 33 whereupon air under pressure is delivered the throttle valve I0 through the inlet passag K .larly important in the ofiset' handle type of hamr'ner because in this type the'trigger movement the ppgqsite direction to thepressure applied by the operators hand for holding the rivet I! to the valve mechanism l l for operation ,of

the hammer. The tapered cleaii ari qvicles not only fine air metering to enable giving signal raps but it also permits fine control of the speed.

In fact, this throttle valve to gives such tivity in regard to speed governing, that ,an. air regulator is usually not necessary, althoughone is shown at 34 connected, as at 35, to the lower end bf the handle fbetw'e'nt strewn) and the handle),

into t-h'e {hammer f hose will 'fb egnheeted {The trig er in accdr" anc tii i gdf l l g t V .set The comfort obtained by this ree 'finger grip reduces finger ,'1and, of course, that is greatl'y' appreciated" by all operators, and especially n the rivet. el '01 twomen Ydper'ators.

team;

{Ifhe air regulator 34 comprises an elongated, tubular body with an angular branch portion 41 cast integral therewith. A va a1- to thelt'gfigittid a' axis V e6b1aerate wita be el'fl' al-v'e p ra nne er a thread ree threads-in the bore 51 cf th 9 el ea th a 'pr'essfit a yrir'r' iiiear piug: 531:1 an e nwaraly agree teat tapered eie et snugly teeter 53, 'djizstd pb'sition.

pin '4 desired to increase ordecrease j eaa 'mer the operater pal e 6 1' hto mic-(5 it" i portion or the'jharfdlje betwri h at b, k wallsis w de end fi i i h .blish e t V The;f :i nd th st l th me ti 'v'e I? "l flhafs "a working fit maso k t empi e far as'I amjawa're this :doubleguide-for the trigger injwhich the valve stem; 211 is-sdisposed parallel to the trigger stem- 31 for bperatiomihua direction substantially .iparal'lel' ate- .:the-': barrel ."4 o'afwh'e hammer, the trigger :bein gripped hytwe or tions and adaptations I claim: 1. 11- a; fluid actuated tool" handle portion in conveying matte sojurl e w thefifll'l actuatedto serving as a valve stem guide and having a counterbored and ported end opening into the passage and providing a valve seat on the end thereof, the other bushing being out of communication with said passage and serving as a trigger guide bushing, a valve reciprocable in the valve stem guide bushing having a head arranged to engage the aforesaid valve seat to close the ported end of said bushing to stop fluid flow from said passage and having an operating stem slidable in said guide and projecting therethrough for operation by the trigger, a trigger abutting the outer end of said stem having a guide stem reciprocable in the trigger guide bushing, and spring means normally closing said valve and holding the trigger in an extreme position relative to said handle.

2. A structure as set forth in claim 1, includlng a pin entered in a hole in the handle in transverse relation to the trigger guide bushing and entering a registering hole in said bushing to hold the same against endwise displacement from said handle, said pin having at least a portion thereof projecting inside the bushing in transverse relation to the bore thereof and entered transversely in a longitudinally extending slot provided in said trigger stem, whereby to hold the trigger against turning relative to said handle about said stem as a center and also to retain said stem and limit endwise movement thereof and accordingly limit movement of the trigger.

3. In a fluid actuated tool, a body having a handle portion in which there is a passage for conveying motive fluid under pressure from a source to the fluid actuated part of the tool, a valve stem guide bushing in said handle in transverse relation to said passage, said bushing having a counterbored and ported end opening into the passage and providing a valve seat on the end thereof, a trigger guide in said handle portion in substantially parallel relation to said valve bushing, a valve reciprocable in the valve bushing having a head arranged to engage the aforesaid valve seat to close the ported end of said bushing to stop fluid flow from said passage and having an operating stem slidable in said guide and projecting therethrough for operation by the trigger, a trigger disposed in transverse relation to the valve bushing and trigger guide and abutting the outer end of said stem and having a guide stem reciprocable in the trigger guide for a parallel sliding relationship between said valve and said guide stem regardless of the location of the point of application of pressure on said trigger, and spring means normally closing said valve and holding the trigger in an extreme position relative to said handle.

4. A structure as set forth in claim 3, including a pin entered in a hole in the handle in transverse relation to the trigger guide and. entered transversely in a longitudinally extending slot provided in said trigger stem, whereby to hold the trigger against turning relative to said handle about said stem as a center and also to retain said stem and limit endwise movement thereof and accordingly limit movement of the trigger.

5. In a fluid actuated tool, a body having a handle portion in which there is a passage for conveying motive fluid under pressure from a source to the fluid actuated part of the tool, a valve stem guide bushing in said handle in trans- I Number verse relation to said passage, said bushing having a counterbored and ported end opening into the passage and providing a valve seat on the end thereof, a trigger guide in said handle portion in substantially parallel relation to said valve bushing, a valve reciprocable in the valve bushing having a head arranged to engage the aforesaid valve seat to close the ported end of said bushing to stop fluid flow from said passage and having an operating stem slidable in said guide and projecting therethrough for operation by the trigger, an elongated trigger disposed in transverse relation to the valve bushing and trigger guide and abutting near its one end the outer end of said stem and having a guide stem near its other end reciprocable in the trigger guide, the trigger guide and valve stem guide being mounted for parallel sliding movement regardless of the location of the point or points of application of finger pressure on said trigger, and spring means normally tending to close the valve and return the trigger to retracted position.

6. In a trigger controlled portable pneumatic tool of the character described, comprising a body having a passage provided therein for conveying motive fluid under pressure, a reciprocable valve in said body controlling fluid flow in said passage having an operating stem projecting outwardly through a guide in the body for operation externally thereof, a single spring holding the valve normally closed, the motive fluid pressure being active in the same direction on the valve, an elongated trigger disposed in transverse relation to and abutting the outer end of said valve stem to open the valve against the spring and motive fluid pressure by finger pressure on the trigger, and a trigger guide stem in rigid transverse relation to and projecting from the trigger in the same direction as the valve stem and in spaced parallel relation to the latter and slidably and non-rotatably received for limited reclprocatory movement in a guide provided therefor in said body so as to slide in unison and parallelism with the valve stem in the manual operation of the trigger.

ERNEST H. FORSS.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Name Date 574,924 Manning Jan. 12, 1897 578,603 Hill Mar. 9, 1897 1,322,035 Madigan Nov. 18, 1919 1,328,578 Malby Jan. 20, 1920 1,720,389 Binks July 9, 1929 1,720,705 Waterman July 16, 1929 1,825,864 Harter Oct. 6, 1931 1,950,122 Nave Mar. 6, 1934 2,101,159 Stevens Dec. 7, 1937 2,102,303 Bramsen Dec. 14, 1937 2,200,322 Arnesen May 14, 1940 2,330,176 Kahn Sept. 21, 1943 2,334,686 Binnall Nov. 16, 1943 2,338,157 Allen Jan. 4, 1944 2,369,776 Forss Feb. 20, 1945 2,393,442 Yellott Jan. 22, 1946 2,395,018 Sherman Feb. 19, 1946 2,447,968 Trotter Aug. 24, 1948 

